Currently I have an old Pentium IV with 2gb RAM, 160gb system disk for the OS and 4 x 1TB drives for media content (1Tb for Recorded TV (700 hours capacity), 1TB for DiVX/AVI movies, 1TB for TV Caps and 1TB for Music and Pictures), 1 DVD ROM, 1 X Plextor DVDRW, Card Reader, Gigabit Ethernet, Hauppauge TV-Nova PCI TV card and a 512MB HDMI out graphics card. This is hooked directly into a Samsung Series 9 46" LCD TV and the sound runs into a fairly low rent 5.1 Surround Sound.
The stuff that's gonna get changed is as follows:
Motherboard - Gigabyte GA-EX58-EXTREME which is an Intel Core-i7 X58-Express board with DDR3 RAM.
CPU - IntelĀ® Core i7-920 Processor (8M Cache, 2.66 GHz)
RAM - Kingston KHX16000D3T1K3/6GX DDR3
TV Tuner - Hauppauge PCI Express Dual Tuner WinTV-HVR-2200 MC
AMP - Onkyo TX-SR 607 AV Receiver (Full 7.1 HD Audio/HDMI Outputs)
Speakers - Kef 3005SE K2's in gloss black
Acquisition wise I already have the mobo and RAM and hopefully next week will have the KEF's and Onkyo. Most likely I'll use the Onky and KEF's immediately on my current system until I splash for the i7 CPU, at which point I can rebuild my Media Center and reload it with Windows 7 Ultimate. I'll post up some more pix when there's a bit more progress but below is some of the kit that's either coming or already in use at Billy Goat Towers.
KEF 'Eggs'

Samsung Series 9 46" LCD (LE46A956D1MXXU)

Onkyo TX-SR 607 - Front

Onkyo TX-SR 607 - Rear

The 'Onk' has plenty of future proofing built in, I can add two more satellite speakers and turn it into a 7.1 system or I could add these, plus a second sub and have a full 7.2 system (my neighbours would hate me though